Zipper foot attachments



Oct. 31, 1967 R. B. HOWELL ZIPPER FOOT ATTACHMENTS 3 Sheets-Sheet 1 Filed Oct. 22, 1965 M 4 w mac r i a BMW Oct. 31, 1967 R. B. HOWELL 3,349,736

ZIPPER FOOT ATTACHMENTS Filed Oct. 22, 1965 3 Sheets-Sheet 2 IN VENTOR. 05627 5. HOWELL R. B. HOWELL ZIPPER FOOT ATTACHMENTS Z Sheets-Shet 3 Filed Oct. '22, 1965 NVEN TOR. @5592- 6. HOWE A rive/V5115 United States Patent 3,349,736 ZIPPER FOOT ATTACHMENTS Robert B. Howell, 2115 Madrona Point Drive, Bremerton, Wash. 98310 Filed Oct. 22, 1965, Ser. No. 501,066 16 Claims. (Cl. 112235) ABSTRACT OF THE DISCLOSURE A pressure foot attachment for a sewing machine comprising a foot component including a transverse slide bar of an upright elongated T-form, and mounting shank means comprising three selectively usable shank components, each including at least one T-shaped slideway for receiving the slide bar and which is slightly undersized in comparison to the slide bar, but is formed by jaws which are sufiiciently resilient to spring apart and permit forceable entry of the slide bar into the slideway; a first mounting shank of channel form including a slideway at its lower end formed by opposed grooves in the flanges of the channel, and a cut away portion of the web, and an upwardly opening blind slot formed in the upper portion of the web for receiving a shank portion of the clamp screw for a low-bar type of presser bar that is equipped with a side placed clamp screw; a second mounting shank equipped with a slideway and a blind slot at each of its ends, both of which are generally like the slideway and blind slot of the first shank, with the slideway at one end placing the shank generally perpendicular to the foot component, and being for use with a conventional high-bar type of presser foot equipped with a side placed clamp screw, and with the slideway at the opposite end placing the shank at approximately the same angle to the foot component as the needle of a slant needle machine is to the sewing machine table; a third mounting shank comprising a cavity at its upward end entering into it from the rear and generally perpendicularly to the presser bar in a plane parallel to the plane of the slideway at its lower end, said upper cavity being sized to receive the head of the clamp screw of the type that is coaxially related to the presser bar; a foot component with parallel side placed zipper teeth guides, a pair of side placed needle receiving recesses for use with such guides, a pair of interior zipper teeth guides formed by a central longitudinal groove in the bottom of the foot component and an inverted ridge and dividing it into two parallel channels, and a central needle aperture for use with said interior guides, with the bottom of the inverted ridge being laterally rounded and spaced above the bottom surfaces of the foot components, and with the two channels leaning outwardly; and a foot component formed to include a central bottom groove divided only at its front end into a pair of outwardly tilted channels, and laterally open rearwardly of a central needle aperture.

This application is a continuation-in-part of my copending application Ser. No. 475,486, filed July 28, 1965, and entitled, Universal Presser Foot Attachment.

The present invention relates to a zipper foot attachment for a sewing machine, and more particularly to a zipper foot attachment capable of being used on essentially every make of household sewing machine presently on the market, and for sewing both exposed and concealed zippers.

In a conventional household sewing machine, the up and-down movement of the needle bar which carries the sewing needle is synchronized with the action of an ad Vance mechanism which functions to advance the material being sewed an incremental amount between stitches. In order to obtain a regular, continuous feed the material must be pressed down against the advance mechanism throughout the sewing operation. This function is performed by what is known as a presser foot. This is a plate-like element that is supported in a position over {)he advance mechanism by a component termed a presser A zipper foot is a specialized form of presser foot. It performs the function of an ordinary presser foot, i.e. it presses the material against the advance mechanism, and in addition it serves to guide the zipper tape being sewn into a proper sewing position with respect to the needle. When a zipper is to be sewn to a garment or the like the regular presser foot is removed from the presser bar and the zipper foot is secured in its place.

The zipper foot for any particular make of sewing machine must be provided with means for securing it to the presser bar of such sewing machine, it must include a suitable zipper teeth guide, and it must be supported on the presser bar in a position wherein said guide is laterally spaced the proper distance away from the needle or the sewing path. Some makes of household sewing machines include a presser bar that is flat on one side, and the presser foot is secured to such bar by a horizontal clamp screw that threads into said flat portion. In some of these machines both the needle bar and the presser bar are uprightand in others they tilt rearwardly or are slanted. Some other makes of sewing machines use the same type of clamp screw arrangement, but the presser bar is designed so that when it is in its operative position the clamp screw is located closer to the top of the needle plate. Still other types of household sewing machines have a presser bar that includes an enlarged head at its lower end, a relatively narrow shank extending upwardly from the head to the presser bar proper, and a clamp nut threadably carried by the lower end of the presser bar proper. The presser foot for this type of machine is clamped onto the presser bar between the enlarged head and the clamp nut.

Another variable amongst sewing machines is the lateral spacing of the presser bar relative to the needle or sewing path.

Owing to these differences in presser bar construction and arrangement, a zipper foot attachment made specially for one type of machine is usually not usable on the other types. As a result, it has been necessary for the merchant who sells attachments for all makes of sewing machines to carry an inventory of each type of zipper foot attachment.

A further factor which has increased the number of types of zipper foot attachments on the market is the development of the so-called concealed or invisible zipper. This type of zipper requires a zipper foot with a difi'erent guide arrangement than is provided on a zipper foot for an ordinary exposed or visible zipper.

A principal object of the present invention is to provide a zipper foot attachment that is attachable to essentially all types of presser bars and is otherwise usable with essentially all makes of household sewing machines, thereby eliminating the need for the merchant to carry an inventory of many special types of zipper foot attachments.

Generally speaking, the zipper foot attachment of the present invention comprises a foot component and three,

selectively usable mounting shanks. The foot component is characterized by four, laterally spaced, parallel, separately and selectively usable, zipper teeth guides. It has a pair of parallel side surfaces which constitute two of stantially flat bottom surface on each side of the central groove, a substantially vertical needle receiving recess in each of the side surfaces, and a needle receiving aperture extending vertically through the component substantially midway between the side recesses. The recesses and the aperture are generally aligned across the foot component perpendicularly to the guides. The side pair of guides, and the needle receiving recesses associated therewith, are used for sewing the tapes of exposed or visible zippers, and the two interior guides and the needle receiving aperture are used for sewing the tapes of concealed or invisible zippers.

In preferred form, the central groove in the bottom of the foot component is divided into two separate guide channels or avenues for the zipper chains only at its leading end, and forwardly of the needle receiving aperture. The front of the separator or divider is shaped somewhat like the bow of a boat. Forwardly, it is rounded both vertically and horizontally. In longitudinal section its bottom is of convex curvature, and curves smoothly downardly and rearwardly from an upper forward position whereat it merges into the front end surface of the foot component. Its rear surface is a downward continuation of the front end surface of the central needle re ceiving aperture. Rounded corners are provided where the side and top surfaces of the two zipper chain avenues meet the front end surface of the foot component. Since the divider does not extend the full length of the foot component, there is essentially no frictional interference by the foot component with the zipper teeth, and since all surfaces contacted by the zipper teeth are rounded, there are no sharp corners or edges on which the zipper teeth may catch. As a result of these features, there is essentially no interference by the foot component with the forward progress of the material determined by the rate of movement of the feed mechanism, and essentially no gathering or puckering of the material is experienced. Since the bottom groove is divider free, and thus laterally open, in the region of the needle aperture, and rearwardly thereof, it is possible to stitch closer to the zipper teeth. This is because care does not have to be taken to prevent the thread carried by the needle from contacting the zipper teeth, as must be done in the form having Zipper chain channels which extend the full length of the foot component. A full length channel restrains or prevents the zipper chain from rolling. If the foot component is adjusted so that the needle is too close to the zipper teeth, the thread can be sheared between the needle and an edge of a zipper tooth, like paper in a paper cutter, because the zipper tooth is immovable. However, in using the preferred form of foot component according to the present invention if the needle and needle and thread contact a tooth, such tooth will merely roll inwardly and the thread will not be broken. This is because it takes a larger force to shear the thread than to cause the tooth to roll.

A transverse slide bar is secured to the top of said foot component. It is narrower at its bottom than at its top, and it possesses a substantially uniform cross-sectional shape throughout its entire length. Each of the mounting shanks includes a spring clamp formed by spaced apart clamp parts defining between them a transverse slideway having a transverse configuration that is substantially identical to the transverse configuration of the slide bar. The slideway is slightly undersized in comparison to the slide bar, and the clamp parts are resilient enough that they will spring apart when the slide bar is forceably slid lengthwise relatively endwise into the slideway. The spring clamp serves to frictonally retain the foot component in each selected position of use. The slide bar may be moved relatively through the slideway, for the purpose of laterally adjusting the foot component relative to the sewing path, when it is subjected to a force of sufficient magnitude to overcome the friction forces.

One of the mounting shanks, herein termed the low bar mounting shank, is of channel form and is composed by a pair of parallel flanges and a web interconnected betwene corresponding edges of said flanges. It is adapted to be convertible to a presser bar of a type having a side entry clamp screw. A blind slot is formed in the upper part of the web for receiving the shank portion of the clamp screw when the presser bar is disposed on the flange side of the web, between the flanges, and the head of the clamp screw is disposed on the opposite side of said web. The lower end portions of the flanges extend downwardly below the lower end of the web and together form the aforementioned slideway and spring clamp.

The second type of mounting shank is also of channel form and is also composed of a pair of generally parallel flanges and a web interconnected between corresponding edges of said flanges. This shank is herein referred to as the high bar mounting shank. It differs from the low bar mounting shank in that it is somewhat longer and is formed to include a spring clamp and a mounting slot at each of its ends. Such mounting shank is invertible and is especially adapted so that when the spring clamp at one end thereof is attached to the slide bar of the foot component it is generally perpendicularly related to the foot component and will extend substantially colinearly with a presser bar of the upright type. When said shank is inverted and the spring clamp at its other end is attached to said slide bar, the mounting shank leans rearwardly a slight amount from an exactly upright position and will extend substantially colinearly with a presser bar of the slanted type.

The third type of mounting shank is usable with a presser bar of a type having an end clamp composed by an enlarged lower end portion, a relatively narrow neck portion immediately above said lower end portion, and a clamp nut threadable along the presser bar proper, immediately above said neck portion. Such mounting shank comprises a pair of laterally spaced side walls, an end wall interconnected between the side walls at one end of said mounting shank, and a top. The mounting shank is open at the end thereof opposite the end wall. The slideway for the slide bar is formed by grooved lower portions of the side and end walls. The top includes an elongated slot entering into it from the open end of the mounting shank. The side walls of the mounting shank are grooved in the direction of extent of the blind slot, at a level below the top and above the transverse slideway for the slide bar. These slots in the side wall serve to slidably receive opposite edge portions of the enlarged lower end portion of the presser bar when the neck portion of said presser bar is in the blind slot and the clamp nut is screwed down against the top.

Another object of the present invention is to provide a zipper foot attachment that is easy to install, to adjust, and to use; is relatively simple in construction and inexpensive to manufatcure; is attractive; and is durable and capable of enduring long periods of repetitious use.

These and other objects, features, and advantages of the present invention will be apparent from the following description, appended claims and annexed drawing.

Referring to the drawing, wherein like reference characters designate like parts throughout the several views;

FIG. 1 is a fragmentary perspective View taken in the needle region of a sewing machine of a type having a high presser bar equipped with a side entry clamp screw, such view showing a zipper foot attachment according to the present invention installed in an operative position for sewing a tape of an invisible zipper, and showing the needle and needle bar assembly in reference;

FIG. 2 is a perspective view of the foot component shown by FIG. 1, such view being taken from above and looking toward the front and the side of the foot component opposite the side shown by FIG. 1;

FIG. 3 is a cross-sectional view taken across the foot component, substantially along line 3-3 of FIG. 1, such view showing the preferred configuration of the central groove and showing a row of zipper teeth in one of the guide channels;

t FIG. 4 is a perspective view of the mounting shank component shown by FIG. 1, showing the side of such mounting shank that is hidden in FIG. 1;

FIG. 5 is a side elevational view of the zipper foot attachment shown by FIG. 1, looking toward the channel side of the mounting shank and showing the mounting shank attached to the foot component in a manner adapting the assembly for attachment to the presser bar of an upright needle machine, and showing the sewing needle, the needle bar and the presser bar in reference;

FIG. 6 is a view like FIG. 5, but showing the mounting shank turned end for end so as to adapt the assembly for attachment to the presser bar of a slant needle machine;

FIG. 7 is a view like FIG. 5, but with the high bar mounting shank being replaced by a low bar mounting shank;

FIG. 8 is a perspective view of the low bar mounting shank removed from the foot component; V

FIG. 9 is a view similar to FIG. 1, but involving a sewing machine having an end clamp type of presser bar;

FIG. 10 is a perspective view of the mounting shank shown by FIG. 9, detached from the foot component, such view being taken from below and looking towards the rear and one side of said mounting shank, and showing the end clamp portion of the presser bar in reference;

FIG. 11 is a front elevational view of the zipper attachment shown by FIG. 1, showing it adjusted for use in sewing a visible zipper, with the lower portion of the sewing needle being shown in reference and the adjacent side portion of the foot component in section for clarity of illustration of the needle in the recess provided for it, and showing the relationship of such needle to the side guide surface, and further showing the projecting end portion of the slide bar being used for giving stability to the slide mount means when the foot component is positioned so as to extend partially outboardly of the foot component;

FIG. 12 is a top plan view form of the foot component;

FIG. 13 is a longitudinal sectional view taken substantially along line 1313 of FIG. 12, such view showing the divider at the leading end of the foot component in side elevation;

FIG. 14 is a bottom plan view of the foot component illustrated by FIGS. 12 and 13, such view showing that the central groove in the bottom of the foot component is laterally open at and rearwardly of the central needle receiving aperture;

FIG. 15 is a transverse sectional view taken substantially along line 1515 of FIG. 13, and showing the rear end of the divider in elevation;

FIG. 16 is a front elevational view of the foot component, taken from the aspect of line 16-16 of FIG. 13; and

FIG. 17 is a transverse sectional view taken substantially along line 1717 of FIG. 13, and showing the crosssectional configuration of the central groove in the bottom of the foot component in its extent rearwardly of the divider.

Referring more specifically to the several views of the drawing, FIG. 1 shows a reciprocating needle bar 10 (in reference) spaced forwardly of a presser bar 12 of the upright high bar type. Bar 12 is equipped with a side clamp type of presser foot mounting mechanism, and when bar 12 is in its operative position such mounting mechanism is spaced relatively high above the needle plate (hence the name high bar).

The mounting mechanism comprises a flat side surface 14 formed on the lower end portion of bar 12, a threaded of a second, and preferred,

aperture entering into the side of said lower portion, substantially perpendicularly to surface 14 and the sewing path, and a clamp screw 16. Surface 14 is parallel to the sewing path. Clamp screw 16 has a large head, with a flat inner surface that is parallel to surface 14, and a threaded shank that is threadable into and out from said apertilted outwardly away from vertical.

ture for the purpose of varying the distance between surface 14 and the inner surface of the head of clamp screw 16.

In FIG. 1 a zipper foot attachment constructed accord ing to the present invention is shown mounted in an operative position by the presser bar 12. Such attachment consists of two interlocking parts-a foot component 18 and a high bar mounting shank 20. The foot component is shown to be positioned for sewing a tape 22 of an invisible zipper to a piece of material 24. A material advance mechanism (not shown) is located below the material 24 and below that part of component 18 that rests on the presses against the tape 22.

Foot component 18 is shown to be constructed in two parts. The first part is the foot itself, which as illustrated may have rectangular proportions. The second part is an elongated slide bar 26 which is secured to the upper surface of the rear portion of the foot, and with said rear portion forms the heel of the foot component 18.

The two side surfaces 28, 30 of the foot component 18 constitute zipper teeth guides which are used when sewing the tape of visible or exposed zippers, as will hereinafter he explained in greater detail. The guide surfaces 28, 30 are parallel and may be planar and vertically disposed as illustrated. A needle receiving recess 32 is formed in surface 28 and a like recess 34 is formed in surface 30.

The bottom of foot component 18 is formed to include a centrally disposed longitudinal groove 36. Groove 36 is divided into two guide channels 33, 40 by an inverted ridge 42. As best shown by FIG. 3, each guide channel 38, 40 has a concave roof. As the roof surfaces extend inwardly they eventually merge into the laterally rounded or convex lower surface of the inverted ridge 42. The sides of groove 36 take at least a slight reversal in curvature as they extend downwardly from the concave roof surfaces of the channels 38, 40. In its lower extent each such side surface is preferably slightly convex (FIG. 3).

The guide channels 38, 40 are parallel with each other and with the side guide surfaces 28, 30. Channel 38 serves as a guide for the row of teeth carried by one tape of an invisible or concealed zipper, and channel 40 serves as a guide for the row of teeth carried by the opposite tape of such zipper. The channels 38, 40 are each As it will be apparent, this is done so that the stitch line can be located as close as possible to the zipper teeth.

A needle receiving aperture 44 extends generally vertically through the foot component 18 between the channels 38, 40. Such aperture 44 is wide enough so that it cuts across the greater portion of inverted ridge 42 and opens into both grooves 38, 40.

The two needle receiving recesses 32, 34 and the needle receiving aperture 44 are arranged in a generally straight line extending across the toe of the foot component 18 and perpendicularly to the several zipper teeth guides 28, 30, 38, 40, and to the sewing path.

Slide bar 26 is shown to be comprised of a stem 46 and a top flange formed by a pair of laterally protruding lips 48, 50 (FIG. 2, for example). This gives slide bar 26 a T shape in cross-section which is substantially uniform throughout the length of slide bar 26. It may be said that slide bar 26 has a relatively narrow lower portion (stem 46) and a relatively wide upper portion (the top flange composed of 46 plus the lips 48, 50).

Referring now to FIGS. 4 and 5 in particular, the high bar mounting shank 20 is shown to be of channel form and to comprise a pair of spaced apart flanges 52, 54 and a web 56 interconnected between corresponding edges of the flanges 52, 54. Each end of web 56 is provided with an end surface adapted to slidably abut against the side portions of the upper surface of the slide bar 26. The end portions of web 56 are also each formed to include an outwardly opening blind slot. These slots designated 58, 60, respectively, are colinearly related.

At each end of shank 20 the end portions of the flanges 7 52, 54 extend beyond the end of web 20 an amount substantially equal to the depth of slide bar 26. The end portions of the flanges 52, 54 are in effect tines or side parts of a spring clamp. Each is provided with a groove in its inner surface for receiving one of the slide bar lips 48, 50.

At one end of the mounting shank 21) the interiorly grooved end portions of the flanges 52, 54, and the end surfaces of web 56 adjacent thereto, together define a slideway for the slide bar 26. Such slideway has a crosssectional shape that is substantially identical to the crosssectional shape of the slide bar, but it is slightly undersized in comparison to the slide bar. Therefore, the end portions of the flanges 52, 54 must be sprung apart slightly to allow entry of the slide bar 26 into the slideway. This assures a tight fit and results in the slide bar being frictionally retained in any position in which it is set. It also permits easy repositioning of the foot component 18 relative to mounting shank 20. The operator need only exert an endwise force on the slide bar 26 of sufficient magnitude to overcome the friction forces.

As perhaps best illustrated in FIG. 5, the slideway of which grooves 62, 64 are a part is oriented relative to the shank 20 in such a manner that when the slide bar 26 is received in it the mounting shank 20 is perpendicular to the foot component 18 and is colinearly relatable to the upright presser bar 12.

The opposite end of mounting shank 20 is also provided with a spring clamp including a slideway defined by and between the end portions of the flanges 52, 54. Such slideway includes a pair of grooves 66, 68, and it is also slightly undersized in comparison to the slide,

bar 26. It differs from the slideway at the opposite end of mounting shank 20 only in that it is oriented so that when the slide bar 26 is received in it the mounting shank 20 tilts rearwardly and is colinearly relatable to a slanted presses bar 12 of the high bar type. As shown by FIGS. 2 and .6 in particular, the needle receiving recesses 32, 34 and the needle receiving aperture 44 are slightly elongated lengthwise of foot component 18 so as to provide suflicient clearance for the slant needle N, which has a deeper path of movement than the upright needle N, due to its slanted attitude.

Preferably the end portions of flanges 52, 54 are extended laterally for the purpose of elongating the two slideways. In the drawing the extensions are designated 70, 72, 74, 76 respectively.

The blind slots 58, 60 serve two functions. The one that is upwardly positioned receives the shank portion of the clamp screw. As shown in FIG. 1, for example, the lower end portion of the pressure bar 12 is located on the flange side of the web 56, between the flanges 52, 54, with its flat side surface 14 disposed against the inner surface of web 56. The shank portion of clamp screw 16 extends generally horizontally through the upper slot (slot 58 in FIG. 1) and screws into the threaded aperture in bar 12. The flat inner surface of the head of clamp screw 16 is disposed against the outer surface of web 6 when the clamp screw 16 is tightened. The blind slot (slot 60 in FIG. 1) that is downwardly positioned serves to elongate the split between the flange end portions. This increases the flexibility of the flange end portions and enhances their ability to spread.

FIGS. 7 and 8 show the foot component 18 attached to a presser bar 12" of the low bar type (the clamp mechanism is positioned relatively close to the needle plate when such presser bar is in its operative position) by a low bar mounting shank 78. Mounting shank 78, like mounting shank 20, is of channel form and is composed of a pair of spaced apart flanges 80, 82 and a web 84 interconnected between corresponding edges of the flanges 80, 82. One end of mounting shank 78 is formed to be substantially identical to the end of mounting shank 20 that includes grooves 62, 64 (shown in FIG. to be connected to the slide bar 26). In other words, mounting shank 78 comprises a spring clamp at one of its ends which includes a slideway that is oriented relative to the shank 78 in such a manner that when the slide bar 26 is received in it the shank 78 is perpendicular to the foot component 18. The upper end portion of web 84 is formed to include an upwardly opening blind slot 86 for receiving the shank portion of the clamp screw 16'. A shallow blind slot 84 may be formed in the lower portion of web 84 for the purpose of elongating the separation between the end portions of the flanges 80, 82 above the slideway. This is done for the purpose of enhacing the ability of the clamp parts to be sprung apart when the slide bar 26 is forcibly slid endwise relatively into the slideway. The slideway is partially formed by grooves 90, 92 formed in the inner surfaces of the lower end portions of the flanges 80, 82 respectively. Mounting shank 78 is preferably also provided with flange extensions 94, 96 for the purpose of adding length to the slideway.

FIGS. 9 and 10 illustrate still another type of mounting shank, this shank which is designated 98, is used for attaching the foot component 18 to a fourth type of presser bar 10". This type of presser bar is characterized by a disk shaped lower end portion 100, attached to the presser bar proper by a relatively narrow neck, and a clamp screw 102 that is threadable along the lower end portion of the presser bar proper.

Mounting shank 98 is shown to comprise a pair of spaced apart side walls 104, 106, an end wall 108, and a top 110. Mounting shank 98 is open at its end opposite the end wall 108. A T-shaped channel 112 is formed in the lower portion of side wall 104, and an identical channel is formed in the opposite side wall 106, in line therewith. A bottom lip 116 extends inwardly from the lower portion of end wall 108. A pair of relatively narrow lips 118, 120, constituting lower portions of the side walls 104, 108, oppose the lip 116. The lips 116, 118, 120, in part define the said T-shaped channels, and such channels define a transverse slideway for the slide bar 26. This slideway possesses a cross-sectional shape where it passes through the sidewalls 104, 106 that is substantially identical to the cross-sectional shape of the slide bar 26, and is also slightly undersized in comparison to the slide bar 26. Owing to their construction, the lips 116, 118, 120 are sufficiently resilient to spring apart when the clamp bar 26 is forceably slid endwise relatively into the slideway, and they serve to frictionally clamp onto and retain the slide bar 26 in the position in which it is set (like the clamp parts of mounting shanks 20 and 78).

Grooves 124, 126 are formed in the inner surfaces of the side walls 104, 106 at a level below the top 110 and above the transverse slideway. As best shown by FIG. 10, opposite edge portions of the end piece are slidably received in the grooves 124, 126. A blind slot 128, opening away from end wall 108, is formed in the top 110. The narrow neck portion of presser bar 10 is accommodated in this slot 128 when the end piece 100 is engaged by the grooves 124, 126. The mounting shank 98 is then clamped firmly in place by screwing clamp nut 102 down until its lower edge bears tightly against the upper surface of top 110.

In operation: The proper mounting shank for the particular sewing machine being used is first selected. The foot component 18 is connected to such shank by forceably inserting the slide bar 26 relatively into its slideway (in the proper slideway if mounting shank 20 is selected). The mounting shank is then clamped onto the presser bar, and the foot component 18 is moved laterally until the needle (N or N) is aligned with a recess 32, 34 or with the aperture 44, depending on the type of zipper, and the particular tape thereof, that is to be sewn.

FIGS. 1 and 3 show the foot component 10 set in a proper position for sewing the right side tape (relative to the operator) of an invisible zipper. Before sewing the foot component is adjusted on the mounting shank for placing the sewing path as close as possible to the inner terminals of the zipper teeth 130. During the sewing oper-ation (FIG. 3), the zipper teeth are continuously fed into the left hand channel 38 as the material is advanced. The lower surface of the inverted ridge 42 is spaced a sufficient distance above the needle plate so that it does not contact, and hence cannot catch on, the inner terminals of the zipper teeth 130. This is an important feature of the present invention, because if the inverted ridge 42 were to contact the zipper teeth, it would interfere with the steady movement of the zipper tape 22 and the material 24 to which it is being sewn. This would cause the material to gather or pucker between stitches, and such gathering would be noticeable and unsightly on the finished garment. To further reduce the possibility of snagging, the edge formed where the outside wall of channel 38 meets the bottom of foot component 18 is rounded. The portions of zipper teeth 130 that contact the outer side of the channel 38 are substantially straight and have fiat outer surfaces, and thus are not likely to snag.

FIG. 11 shows the foot component 18 shifted to a far right position wherein the needle N is located in recess 32 and side guide 28 is in operative position for sewing the right side tape 132 of a conventional visible or exposed zipper to a piece of material 134. The slide bar 26 is constructed to be longer than the foot component 18 is wide so that when the two parts are in the position illustrated by FIG. 11 (or moved to a far left position) the full length of the slideway is occupied by a portion of the slide bar 26. This gives stability and rigidity to the connection between the mounting shank and the foot component.

As should be apparent from the foregoing, the foot component 18 may be moved sideways relative to the sewing path by merely subjecting it to a lateral force in the direction of desired movement that is sufiicient magnitude to overcome the friction forces. When the force is removed and the foot component is set into a particular position, it will be held or retained in such position by the friction forces acting where the side lips 43, 50 mate with the grooves in the side parts of the slideway.

Some sewing machines (e.g., zig-zag machines) have a normal sewing position located further to the left than to the standard straight stitch machine. With this type of machine the foot component 18 is merely forced an -additional distance sideways in order to properly locate it with respect to the needle N and the sewing path.

Referring now to FIGS. 12-17, depicting a modified form of foot component, designated 18', it is to be noted that the inverted divider 42' of such form is located en tirely forwardly of the central needle aperture 44. From front to rear the divider 42' is convexly rounded both vertically and horizontally, and has an appearance similar to the bow of a round bottom boat. The rear surface 131 of the divider 42' is a downward extension of the forward end wall of the aperture 44.

In similar fashion to foot component 18, and for the same reasons (FIGS. 13, for example) the two zipper chain channels on the opposite sides of the divider 42 are tilted outwardly somewhat away from vertical. Rearwardly of the rear surface 131 of the divider 32', the central groove 36 is laterally open (FIG. 17). In this region the roof of the groove 36' is substantially flat, and is above the uppermost part of the zipper teeth passing relatively through the groove 36'.

As clearly shown by FIG. 16, for example, rounded corners are provided where the side and top surfaces of the two zipper chainchannels or avenues meet the front end surface of the foot component 18', and as previously described the divider 42' is forwardly rounded. Collectively these rounded corners and surfaces define smoothly rounded entrances for the zipper teeth. Relatively sharp edges may be formed at the intersections of the side surfaces of the divider 42' and the rear surface 131, and at the lower peripheral edge of the aperture 44'. However, owing to the construction of the foot component 18, these edges are out of the path of travel of the zipper teeth. Since the divider 42' does not extend the full length of the foot component 18', there is essentially no frictional interference by the foot component with the zipper teeth. Since all surfaces contacted by the zipper teeth are rounded, there are no sharp corners or edges on which the zipper teeth may catch. As a result of these features, there is essentially no interference by the foot component with the forward progress of the material determined by the rate of movement of the feed mechanism, and essentially no gathering or puckering of the material is experienced.

Since the bottom groove 36' is laterally open in the region of the needle aperture, and rearwardly thereof, it is possible to stitch closer to the zipper teeth than with the form illustrated byFIGS. 1-3, 57, 9 and 11. This is because care does not have to be taken to prevent the thread carried by the needle from contacting the zipper teeth, as must be done when the prior form 18 having zipper chain channels extending the full length of the foot component is used. The full length channel Iestrains the zipper chain laterally, and prevents it from rolling. If the foot component is adjusted so that the needle is too close to the Zipper teeth, the thread can be sheared between the needle and an edge of a zipper tooth, like paper ina paper cutter, because the zipper tooth is immovable. However, in using the preferred 'form of foot component according to the present invention, if the needle and thread contact a tooth, such tooth will merely roll inwardly and the thread will not be broken. This is because it takes a larger force to shear the thread than to cause the tooth to roll.

From the foregoing, further variations, modifications, adaptations and usages of zipper foot attachments according to the present invention will be apparent within the scope of the following claims.

What is claimed is:

1. A zipper foot attachment for a sewing machine, comprising: a foot component wit-h four, laterally spaced, parallel, separately and selectively useable, zipper teeth guides, said foot component having a pair of parallel side surfaces constituting two of said guides, a bottom groove, a downwardly projecting divider dividing only the leading part of the bottom groove into separate channels constituting the other two guides, a substantially flat bottom surface on each side of said central groove, a substantially vertical needle receiving recess formed in each of said side surfaces, and a substantially vertical needle receiving aperture extending through said foot component substantially midway between said recesses, and said recesses and said aperture being generally aligned across the foot component perpendicularly to said guides.

2. A zipper foot attachment according to claim 1, wherein the bottom of the downwardly projecting divider is laterally rounded, and is spaced above the bottom surfaces of the foot component a sufiicient distance that in use it is located above, and therefore will not contact and catch on, the inner terminals of the zipper "teeth.

3. A zipper foot attachment according to claim 1, wherein the downwardly projecting divider is disposed substantially entirely forwardly of the needle receiving aperture, and the bottom groove is laterally open and its roof is substantially fiat and above the zipper teeth at and rearwardly of said aperture, so that a zipper tooth is free to roll inwardly if struck by the needle as it moves downwardly through said aperture.

4. A zipper foot attachment according to claim 3, wherein the downwardly projecting divider is convexly rounded both vertically and horizontally, from front to rear, and wherein the rear surface of said divider is a downward extension of the forward end wall of said aperture.

5. A zipper foot attachment according to claim 4, wherein the entrances of the two channels are inwardly rounded and wherein said channels are tilted outwardly away from vertical.

6. A zipper foot attachment for a sewing machine, comprising: a foot component with four, laterally spaced, parallel, separately and selectively useable zipper teeth guides, said foot component having a pair of parallel side surfaces constituting two of said guides, a central groove including an inverted ridge dividing it into two, parallel channels constituting the other two guides, a substantially flat bottom surface on each side of said central groove, a substantially vertical needle receiving recess formed in each of said side surfaces, and a substantially vertical needle receiving aperture extending through said inverted ridge between said channels, said recesses and said aperture being aligned across the foot component perpendicularly to said guides.

7. A zipper foot attachment according to claim 6, wherein the bottom of the inverted ridge is laterally rounded, and is spaced above the bottom surfaces of the foot component a suflicient distance that in use it is located above, and therefore will not contact and catch on, the inner terminals of the zipper teeth.

8. A zipper foot attachment for a sewing machine equipped with a presser bar, a material advance mechanism, and a recipricating needle bar and needle assembly, said attachment comprising: a foot component with four, laterally spaced, parallel, separately and selectively useable zipper teeth guides, said foot component having a pair of parallel side surfaces constituting two of said guides, a bottom groove, a downwardly projecting divider dividing at least the leading end of he bottom groove into separate channels constituting the other two guides, a substantially flat bottom surface on each side of said central groove, a substantially vertical needle receiving recess formed in each of said side surfaces, and a substantially vertical needle receiving aperture extending through said foot component between said recesses, said recesses and said aperture being generally aligned across the foot component perpendicularly to said guides, said foot component also including one component of a two component slide mount means; and a mounting shank connectable to the presser bar, said mounting shank including a lower end portion constituting a second component of said slide mount means, with said slide mount means and said mounting shank serving to mount the foot component onto the presser bar in a position wherein its bottom surfaces are positionable over the material advance mechanism, and the needle receiving recesses and the needle receiving aperture are aligned with the needle across the sewing pat-h, and with said slide mount means mounting said foot component onto said mounting shank in a manner permitting lateral adjustment of said foot component on said mounting shank, relative to the needle.

9. A zipper foot attachment according to claim 8, wherein the bottom of the downwardly projecting divider is laterally rounded, and is spaced above the bottom surfaces of the foot component a sufficient distance that in use it is located above, and therefore will not contact and catch on, the inner terminals of the zipper teeth.

10. A zipper foot attachment according to claim 8,

wherein the downwardly projecting divider is disposed substantially entirely forwardly of the needle receiving aperture, and the bottom groove is laterally open and its roof is substantially fiat and above the zipper teeth at and rearwardly of said aperture, so that a zipper tooth is free to roll inwardly rearwardly of it struck by the needle as it moves downwardly through said aperture.

11. A zipper foot attachment according to claim 10, wherein the downwardly projecting divider is convexly rounded both vertically and horizontally, from front to rear, and wherein the rear surface of said divider is a downward extension of the forward end wall of said aperture.

12. A zipper foot attachment according to claim 11, wherein the entrances of the two channels are inwardly rounded and wherein said channels are tilted outwardly away from vertical.

13. A zipper foot attachment for a sewing machine, comprising: a foot component having a longitudinal bottom groove, a downwardly projecting divider dividing the leading end of the bottom groove into two separate zipper teeth guide avenues, a substantially flat bottom surface on each side of said central groove, and a substantially vertical needle receiving aperture extending through said foot component substantially midway between said avenues, with said divider being disposed forwardly of the needle receiving aperture, and said bottom groove being laterally undivided and spaced above the zipper teeth immediately behind said needle receiving opening so that a zipper tooth is free to roll inwardly if struck by the needle as it moves downwardly through said aperture.

14. A zipper foot attachment according to claim 13, wherein the bottom of the downwardly projecting divider is laterally rounded, and is spaced above the bottom surfaces of the foot component a sufficient distance that in use it is located above, and therefore will not contact and catch on, the inner terminals of the zipper teeth.

15. A zipper foot attachment according to claim 13, wherein the downwardly projecting divider is convexly rounded both vertically and horizontally, from front to rear, and wherein the rear surface of said divider is a downward extension of the forward end wall of said aperture.

16. A zipper foot attachment according to claim 15, wherein the entrances of the two channels are inwardly rounded and wherein said channels are tilted outwardly away from vertical.

References Cited UNITED STATES PATENTS 1,930,628 10/1933 Smallbone 112240 2,909,136 10/1959 Dixon et al. 112-235 3,011,459 12/1961 McNamara 112-235 3,098,460 7/ 1963 Yoshida 112235 3,251,326 5/1966 Howell 112-235 3,259,090 7/1966 Howell 112-240 3,294,048 12/1966 Micale 112-240 PATRICK D. LAWSON, Primary Examiner. 

1. A ZIPPER FOOT ATTACHMENT FOR A SEWING MACHINE, COMPRISING: A FOOT COMPONENT WITH FOUR, LATERALLY SPACED, PARALLEL, SEPARATELY AND SELECTIVELY USEABLE, ZIPPER TEETH GUIDES, SAID FOOT COMPONENT HAVING A PAIR OF PARALLEL SIDE SURFACES CONSTITUTING TWO OF SAID GUIDES, A BOTTOM GROOVE, A DOWNWARDLY PROJECTING DIVIDER DIVIDING ONLY THE LEADING PART OF THE BOTTOM GROOVE INTO SEPARATE CHANNELS CONSTITUTING THE OTHER GUIDES, A SUBSTANTIALLY FLAT BOTTOM SURFACE ON EACH SIDE OF SAID CENTRAL GROOVE, A SUBSTANTIALLY VERTICAL NEEDLE RECEIVING RECESS FORMED IN EACH OF SAID SIDE SURFACES, AND A SUBSTANTIALLY VERTICAL NEEDLE RECEIVING APERTURE EXTENDING THROUGH SAID FOOT COMPONENT SUBSTANTIALLY MIDWAY BETWEEN SAID RECESSES, AND SAID RECESSES AND SAID APERTURE BEING GENERALLY ALIGNED ACROSS THE FOOT COMPONENT PERPENDICULARLY TO SAID GUIDES. 